In the manufacture of large medical X-ray detectors many challenges have to be overcome. Planar components subject to stringent flatness requirements must be bonded together by an adhesive layer of well-defined thickness without air pockets. This is particular true of the image sensor and the interface layer that goes on top. In order to completely fill the gap between the two planar components with adhesive, considerably more adhesive must be applied than is actually required. As the planar components are brought together the surplus adhesive is squeezed out of the sides. This surplus adhesive must be removed since otherwise it risks contaminating the remainder of the detector. The problem is compounded by the fact that random surface effects can lead to an unpredictable wicking path, so it is not known in advance where the surplus adhesive will end up.
US patent publication No. 2009/0108473 discloses a method wherein excess adhesive flows into a recessed region to prevent material from creeping up the sides of an integrated circuit chip.